U.S. Pat. No. 4,981,724 discloses and claims a process for chemically vapor depositing silicon oxide on a heated substrate utilizing a silane selected from the group consisting of alkylsilane, arylsilane, alkoxysilanes, alkynylsilane, and aralkylsilane reacted with oxygen. Among other things, the process of the patent requires the substrate being heated to a minimum temperature of 325.degree. C. in order to effect deposition.
The semiconductor industry is constantly in search of ways to reduce the minimum temperatures required for safe chemical vapor deposition to provide silicon dioxide films under conditions of high deposition rates and good film quality. This lower temperature requirement is necessitated by materials of construction for substrates, such as aluminum and/or plastics.
The aforementioned patent is an attempt to lower the temperature of deposition in order to accommodate some of the newer substrates. In fact, the patentees discovered that the use of diethylsilane in the presence of oxygen would result in a satisfactory deposition of silicon dioxide at a minimum substrate temperature of 325.degree. C. (620.degree. F.).
In the past, there have been attempts to identify promoters for use with silicon dioxide precursors in order to enhance the silicon dioxide deposition process. Ozone has been used to promote silicon dioxide deposition from tetraethoxysilane (TEOS)-oxygen systems and tetramethylsilane-oxygen systems, as reported by K. V. Guinn and J. A. Mucha in "Chemical Vapor Deposition of SiO.sub.2 From Ozone-Organosilane Mixtures Near Atmospheric Pressure", Mat. Res. Soc, Symp. Proc., Vol. 282, 1993, pp. 575-580. However, the use of ozone requires the use of a separate ozone generator and is an environmental concern for operators.